What does 'polyfill' mean？

[shanechiu]

I ofen see polyfill words in documents. I wonder know what it points?

I quote wikipedia:

In web development, a polyfill is code that implements a feature on web browsers that do not support the feature. Most often, it refers to a JavaScript library that implements an HTML5 web standard, either an established standard (supported by some browsers) on older browsers, or a proposed standard (not supported by any browsers) on existing browsers. Formally, "a polyfill is a shim for a browser API".

As a result, polyfill is a tools supporting a no-built in feature.

It is not just belong to web browsers,more than web development.

[hjdtl]

百度了一下，感觉这个答案还不错： https://segmentfault.com/a/1190000002593432

[SourceMan]

Google 了一下，感觉这个答案还不错： https://stackoverflow.com/questions/7087331/what-is-the-meaning-of-polyfills-in-html5

[kamal]

从一楼的链接找到的 https://remysharp.com/2010/10/08/what-is-a-polyfill

[serco]

英文不忍直视啊。。。

[robinlovemaggie]

简单点说兼容新老浏览器的库就是 polyfill，否则不是。例如，jQuery 不是，Polymer, FlashCavas 是。

[Mutoo]

If you want to use an edge or modern feature on a widespread old browser (e.g. es2015 Promises), you can use the polyfill (e.g. Promises-polyfill), if the new feature is not internal provided but can be implemented within the current javascript's scope.

[shanechiu]

@Mutoo well,thanks a lot.

[shanechiu]

@hjdtl I read the article throughly, it is fully. Thank you for your recommendation.